Phase separation in bilayer lipid membranes: Effects on the inner leaf due to coupling to the outer leaf
Phase separation in bilayer lipid membranes: Effects on the inner leaf due to coupling to the outer leaf
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DOI：
10.1529/biophysj.106.086868
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发表时间：
2006-10-01
影响因子：
3.4
通讯作者：
Schick, M.
中科院分区：
文献类型：
--
作者：
Allender, D. W.;Schick, M.
利用朗道自由能理论上研究了胆固醇在液相中排列脂质的倾向和双层两叶中脂质之间的耦合的综合效应。我们表明，作为这些综合效应的结果，在外部叶片之间的横向相分离胆固醇丰富和-贫液体导致类似的，但较弱的，相分离的内部叶片。正如外层叶片中的脂质面密度在富含胆固醇的区域增加一样，内层叶片中的脂质面密度也增加。因此，内叶的面密度在空间上变化，反映了外叶的面密度的空间变化。这提供了一种机制，使蛋白质通过碳氢化合物系链附着在内叶上，以响应外叶组成的变化。我们还注意到，在人工双层中，应该可以观察到叶子之间的耦合效应。
The combined effects of the tendency of cholesterol to order lipids in the liquid phase and the coupling between lipids in the two leaves of a bilayer are investigated theoretically utilizing a Landau free energy. We show that as a consequence of these combined effects, lateral phase separation in the outer leaf between cholesterol-rich and -poor liquids causes a similar, but weaker, phase separation in the inner leaf. Just as the areal density of lipids in the outer leaf increases in the cholesterol-rich regions, so the areal density of lipids also increases in the inner leaf. Thus, the areal density in the inner leaf varies spatially, reflecting spatial variations of the areal density in the outer leaf. This provides a mechanism for proteins attached to the inner leaf via a hydrocarbon tether to respond to variations in the composition of the outer leaf. We also note that the effect of coupling between the leaves should be observable in artificial bilayers.